Convex combination adaptive echo cancellation method for affine projection sign subband adaptive filter

Abstract

The invention discloses a convex combination adaptive echo cancellation method for an affine projection sign subband adaptive filter. The method mainly comprises the following steps: A, far-end signal filtering: performing far-end signal filtering to obtain the output vector Y1(n) of a large-step-length filter and the output vector Y2(n) of a small-step-length filter; B, convex combination: performing convex combination on the output vector Y1(n) and the output vector Y2(n) of the large-step-length filter and the small-step-length filter to obtain a combination filtering value Y(n) (Y(n)= lambda(n)Y1(n)+(1-lambda(n))Y2(n)), and performing convex combination on the tap weight vector W1(n) of the large-step-length filter and the tap weight vector W2(n) of the small-step-length filter to obtain a total filter group tap weight vector W(n) (W(n)=lambda(n)W1(n)+(1-lambda(n))W2(n); C, echo cancellation: subtracting the combination filter value Y(n) from an echo-carrying affine projection near-end signal D(n) picked up by a near-end microphone to obtain a net signal E(n) (E(n)=D(n)-Y(n)), and transmitting the net signal back to a far end; D, updating the tap weight coefficients of the filters; E, weight update of the filters: updating hybrid parameters a(n); and F, iteration: repeating the steps above under the condition that n=n+1 till the end of a conversation. The method has the advantages of high cancellation capability on the acoustic echo of a sparse communication system, high convergence speed, small steady-state error and good echo cancellation effect.

Description

technical field [0001] The invention belongs to the technical field of self-adaptive echo cancellation for communication. Background technique [0002] In recent years, with the development of various emerging communications, communication users are increasingly concerned about call quality. In communication systems, the problems of noise and echo interference are often encountered. In the problem of echo interference, acoustic echo (Echo) is the most important factor affecting the quality of voice communication. Acoustic echo during communication refers to the user repeatedly hearing his own voice during communication. This phenomenon is caused by sound wave reflections and acoustic coupling between the microphone and speaker. Acoustic echoes have short delays and are multipath and time-varying. In communication, the human ear is extremely sensitive to this echo. The echo delayed by 10ms can be captured and perceived by the human ear, and the echo exceeding 32ms will ca...

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Problems solved by technology

However, the algorithm still has the inherent contradiction between the convergence speed of the adaptive filter and the steady-state error.

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